Password entry using 3D image with spatial alignment

ABSTRACT

A method of authenticating access on an electronic device. A digital image overlaid by an array of alphanumeric characters is displayed on a three-dimensional display of the electronic device. The digital image includes a three-dimensional representation of a scene and is displayed in three-dimensional coordinates. The array of alphanumeric characters is positioned on the three-dimensional display with respect to the digital image in three dimensions in response to received input. Access to the electronic device is authenticated in response to detecting that a designated character in the digital image is aligned with a designated object in the digital image.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 12/969,633, filed Dec. 16, 2010. The present application is related to commonly owned U.S. patent application Ser. No. 12/969,647, entitled “ADJUSTING THE POSITION OF AN ENDPOINT REFERENCE FOR INCREASING SECURITY DURING DEVICE LOG-ON”, U.S. patent application Ser. No. 12/969,878 entitled “VISUAL OR TOUCHSCREEN PASSWORD ENTRY”, U.S. patent application Ser. No. 12/969,646 entitled “PRESSURE-SENSITIVE MULTI-LAYER PASSWORDS”, U.S. patent application Ser. No. 12/969,797 entitled “OBSCURING VISUAL LOGIN”, U.S. patent application Ser. No. 12/969,645 entitled “MULTI-LAYER ORIENTATION-CHANGING PASSWORDS”, U.S. patent application Ser. No. 12/969,643 entitled “MULTI-LAYER MULTI-POINT OR PATHWAY-BASED PASSWORDS”, U.S. patent application Ser. No. 12/969,640 entitled “MULTI-LAYERED COLOR-SENSITIVE PASSWORDS”, U.S. patent application Ser. No. 12/969,638 entitled “SIMPLE ALGEBRAIC AND MULTI-LAYER PASSWORDS”, U.S. patent application Ser. No. 12/969,637 entitled “MULTI-LAYER MULTI-POINT OR RANDOMIZED PASSWORDS”, and U.S. patent application Ser. No. 12/969,629 entitled “PASSWORD ENTRY USING MOVING IMAGES”. The entire contents of the above-noted documents is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to graphical authentication.

BACKGROUND

Passwords may be used in many situations where a user needs to be authenticated. Situations requiring authentication may include the ability to access or use a computer, mobile phone, PDA, or any other device. They may also enable access to a physical location, or allow use of a credit/debit card or similar instrument. Passwords are typically alpha-numeric strings or sequences entered on a keyboard. Graphical authentication systems, where passwords are comprised of graphical components, also exist.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a communication system including a mobile communication device in which example embodiments of the present disclosure can be applied;

FIG. 2 is a block diagram illustrating a mobile communication device in accordance with one example embodiment of the present disclosure;

FIG. 3 is a block diagram illustrating an authentication module in accordance with one example embodiment of the present disclosure;

FIGS. 4A and 4B are flowcharts illustrating a method in accordance with one example embodiment of the present disclosure;

FIG. 5 is a block diagram illustrating a computing device in accordance with one example embodiment of the present disclosure;

FIG. 6 is a block diagram illustrating a computing device in accordance with one example embodiment of the present disclosure;

FIGS. 7A to 7D are screen shots illustrating one example embodiment of the present disclosure;

FIGS. 8A and 8B are screen shots illustrating one example embodiment of the present disclosure.

Like reference numerals are used in the drawings to denote like elements and features.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In some graphical authentication systems, a user must move a previously selected reference point on an overlay image, such as a grid, to a previously selected reference point on a base image. With existing graphical authentication systems, “shoulder surfing” can occur. For example, a third party observer may be able to determine where a cursor is located at the end of the authentication process. In some situations, a third party observer may observe where the user's fingers are pointing. In other situations, a computer algorithm could be used to determine a pattern of where certain points on the overlay image are located at the end of the authentication process.

Thus, the present disclosure proposes a graphical authentication system in which a three-dimensional reference point on one image must be aligned with a reference point on another image.

In accordance with one aspect of the present disclosure, there is provided a method of controlling access to an electronic device, comprising: generating a modified first image from a first image, wherein the first image and the modified first image include a first image reference point; generating a modified second image from a second image, wherein the second image and the modified second image include a second image reference point; displaying a three dimensional representation of the modified first image overlaid by the modified second image; authenticating access to the electronic device in response to substantial alignment of the first image reference point in the modified first image with the second image reference point in the modified second image.

In accordance with another aspect of the present disclosure, there is provided a generating a modified base image from a base image, wherein the base image and the modified base image include a base image reference point; generating a modified overlay image from an overlay image, wherein the overlay image and the modified overlay image include an overlay image reference point; displaying a three dimensional representation of the modified base image overlaid by the modified overlay image; authenticating access to the electronic device in response to alignment of the base image reference point in the modified base image with the overlay image reference point in the modified overlay image.

In accordance with a further aspect of the present disclosure, there is provided a method of authenticating a user of a computing device, the computing device having a memory storing a base image and an overlay image, the base image having a pre-selected base image reference point, and the overlay image having an overlay image reference point, the method comprising: generating a modified base image; generating a modified overlay image; displaying, on a display, the modified base image overlaid by the modified overlay image; receiving an input for moving one of the modified base image and the modified overlay image; moving the one of the modified base image and the modified overlay image in response to the input; and in response to alignment of the base image reference point with the overlay image reference point on the display, indicating positive authentication, at least one of the base image reference point and the overlay image reference point having coordinates in three dimensions.

In accordance with yet a further aspect of the present disclosure, there is provided an electronic device, comprising: a processor; a display coupled to the processor; a memory coupled to the processor storing instructions that, when executed by the processor, cause the processor to perform any one or more of the methods described herein.

In accordance with yet a further aspect of the present disclosure, there is provided a non-transitory machine readable medium having tangibly stored thereon executable instructions that, when executed by a processor of an electronic device, cause the processor to perform any one or more of the methods described herein.

Embodiments of the present application are not limited to any particular operating system, mobile device architecture, server architecture, or computer programming language.

Reference is first made to FIG. 1 which shows in block diagram form a communication system 100 in which example embodiments of the present disclosure can be applied. The communication system 100 comprises a number of mobile communication devices (mobile devices) 201 which may be connected to the remainder of system 100 in any of several different ways. Accordingly, several instances of mobile communication devices 201 are depicted in FIG. 1 employing different example ways of connecting to system 100. Mobile communication devices 201 are connected to a wireless communication network 101 which may comprise one or more of a Wireless Wide Area Network (WWAN) 102 and a Wireless Local Area Network (WLAN) 104 or other suitable network arrangements. In some embodiments, the mobile communication devices 201 are configured to communicate over both the WWAN 102 and WLAN 104, and to roam between these networks. In some embodiments, the wireless network 101 may comprise multiple WWANs 102 and WLANs 104.

The WWAN 102 may be implemented as any suitable wireless access network technology. By way of example, but not limitation, the WWAN 102 may be implemented as a wireless network that includes a number of transceiver base stations 108 (one of which is shown in FIG. 1) where each of the base stations 108 provides wireless Radio Frequency (RF) coverage to a corresponding area or cell. The WWAN 102 is typically operated by a mobile network service provider that provides subscription packages to users of the mobile communication devices 201. In some embodiments, the WWAN 102 conforms to one or more of the following wireless network types: Mobitex Radio Network, DataTAC, GSM (Global System for Mobile Communication), GPRS (General Packet Radio System), TDMA (Time Division Multiple Access), CDMA (Code Division Multiple Access), CDPD (Cellular Digital Packet Data), iDEN (integrated Digital Enhanced Network), EvDO (Evolution-Data Optimized) CDMA2000, EDGE (Enhanced Data rates for GSM Evolution), UMTS (Universal Mobile Telecommunication Systems), HSDPA (High-Speed Downlink Packet Access), IEEE 802.16e (also referred to as Worldwide Interoperability for Microwave Access or “WiMAX), or various other networks. Although WWAN 102 is described as a “Wide-Area” network, that term is intended herein also to incorporate wireless Metropolitan Area Networks (WMAN) and other similar technologies for providing coordinated service wirelessly over an area larger than that covered by typical WLANs.

The WWAN 102 may further comprise a wireless network gateway 110 which connects the mobile communication devices 201 to transport facilities 112, and through the transport facilities 112 to a wireless connector system 120. Transport facilities may include one or more private networks or lines, the public internet, a virtual private network, or any other suitable network. The wireless connector system 120 may be operated, for example, by an organization or enterprise such as a corporation, university, or governmental department, which allows access to a network 124 such as an internal or enterprise network and its resources, or the wireless connector system 120, may be operated by a mobile network provider. In some embodiments, the network 124 may be realised using the internet rather than an internal or enterprise network.

The wireless network gateway 110 provides an interface between the wireless connector system 120 and the WWAN 102, which facilitates communication between the mobile communication devices 201 and other devices (not shown) connected, directly or indirectly, to the WWAN 102. Accordingly, communications sent via the mobile communication devices 201 are transported via the WWAN 102 and the wireless network gateway 110 through transport facilities 112 to the wireless connector system 120. Communications sent from the wireless connector system 120 are received by the wireless network gateway 110 and transported via the WWAN 102 to the mobile communication devices 201.

The WLAN 104 comprises a wireless network which, in some embodiments, conforms to IEEE 802.11x standards (sometimes referred to as Wi-Fi) such as, for example, the IEEE 802.11a, 802.11b and/or 802.11g standard. Other communication protocols may be used for the WLAN 104 in other embodiments such as, for example, IEEE 802.11n, IEEE 802.16e (also referred to as Worldwide Interoperability for Microwave Access or “WiMAX”), or IEEE 802.20 (also referred to as Mobile Wireless Broadband Access). The WLAN 104 includes one or more wireless RF Access Points (AP) 114 (one of which is shown in FIG. 1) that collectively provide a WLAN coverage area.

The WLAN 104 may be a personal network of the user, an enterprise network, or a hotspot offered by an internet service provider (ISP), a mobile network provider, or a property owner in a public or semi-public area, for example. The access points 114 are connected to an access point (AP) interface 116 which may connect to the wireless connector system 120 directly (for example, if the access point 114 is part of an enterprise WLAN 104 in which the wireless connector system 120 resides), or indirectly via the transport facilities 112 if the access point 14 is a personal Wi-Fi network or Wi-Fi hotspot (in which case a mechanism for securely connecting to the wireless connector system 120, such as a virtual private network (VPN), may be appropriate). The AP interface 116 provides translation and routing services between the access points 114 and the wireless connector system 120 to facilitate communication, directly or indirectly, with the wireless connector system 120.

The wireless connector system 120 may be implemented as one or more servers, and is typically located behind a firewall 113. The wireless connector system 120 manages communications, including email messages, to and from a set of managed mobile communication devices 201. The wireless connector system 120 also provides administrative control and management capabilities over users and mobile communication devices 201 which may connect to the wireless connector system 120.

The wireless connector system 120 allows the mobile communication devices 201 to access the network 124 and connected resources and services such as a messaging server 132 (for example, a Microsoft Exchange™, IBM Lotus Domino™, or Novell GroupWise™ email messaging server) having a global address book 134, and optionally other servers 142. The other servers 142 may comprise a content server for providing content such as internet content or content from an organization's internal servers to the mobile communication devices 201 in the wireless network 101, and an application server for implementing server-based applications.

The global address book 134 comprises electronic contact records generated and maintained by an IT (information technology) administrator of the network 124. Typically, the global address book is maintained exclusively by the messaging server 132 and there is no local copy on the mobile device 201. In addition, the global address book typically comprises contact records for all users of the respective network 124 (e.g., enterprise). The contact records in the global address book 134 may be one or more of individual contact records (or user records) or a group address or distribution list which lists multiple individual (users).

The wireless connector system 120 typically provides a secure exchange of data (e.g., email messages, personal information manager (PIM) data, and IM data) with the mobile communication devices 201. In some embodiments, communications between the wireless connector system 120 and the mobile communication devices 201 are encrypted. In some embodiments, communications are encrypted using a symmetric encryption key implemented using Advanced Encryption Standard (AES) or Triple Data Encryption Standard (Triple DES) encryption. Private encryption keys are generated in a secure, two-way authenticated environment and are used for both encryption and decryption of data.

The wireless network gateway 110 is adapted to send data packets received from the mobile device 201 over the WWAN 102 to the wireless connector system 120. The wireless connector system 120 then sends the data packets to the appropriate connection point such as the messaging server 132, content server 132 or application servers 136. Conversely, the wireless connector system 120 sends data packets received, for example, from the messaging server 132 or other server 142 to the wireless network gateway 110 which then transmit the data packets to the destination mobile device 201. The AP interfaces 116 of the WLAN 104 provide similar sending functions between the mobile device 201, the wireless connector system 120 and network connection point such as the messaging server 132, content server 132 and application server 136.

The network 124 may comprise a private local area network, metropolitan area network, wide area network, the public internet or combinations thereof and may include virtual networks constructed using any of these, alone, or in combination. Computers 117 may be connected to the network 124 directly or indirectly via an intermediate communication network such as the Internet 112. When computers 117 connect to the network indirectly, e.g. via the Internet 112, a VPN or other mechanism for securely connecting to the network 124 may be appropriate. Computers 117 may be of any suitable construction and include at least a processor, and a display screen, one or more user input devices, and a memory each connected to the processor as is known in the art. The computers 117 could be desktop computers, laptop/notebook/netbook computers, or combinations thereof, and may have wired or wireless communication subsystems for connecting to the network 124.

A mobile device 201 may alternatively connect to the wireless connector system 120 using a computer 117 via the network 124. In at least some embodiments, for security purposes the computers 117 with which the mobile devices 201 can connect to the wireless connector system 120 are limited to computers 117 which are directly connected to the network 124. A link 106 may be provided for exchanging information between the mobile device 201 and computer 117 connected to the wireless connector system 120. The link 106 may comprise one or both of a physical interface and short-range wireless communication interface. The physical interface may comprise one or combinations of an Ethernet connection, Universal Serial Bus (USB) connection, Firewire™ (also known as an IEEE 1394 interface) connection, or other serial data connection, via respective ports or interfaces of the mobile device 201 and computer 117. The short-range wireless communication interface may be a personal area network (PAN) interface. A personal area network is a wireless point-to-point connection meaning no physical cables are required to connect the two end points.

It will be appreciated that the above-described communication system is provided for the purpose of illustration only, and that the above-described communication system comprises one possible communication network configuration of a multitude of possible configurations for use with the mobile communication devices 201. The teachings of the present disclosure may be employed in connection with any other type of network and associated devices that are effective in implementing or facilitating wireless communication. Suitable variations of the communication system will be understood to a person of skill in the art and are intended to fall within the scope of the present disclosure.

Reference is now made to FIG. 2 which illustrates an exemplary embodiment of the mobile device 201 in which example embodiments described in the present disclosure can be applied. The mobile device 201 is a two-way communication device having data and voice communication capabilities, and the capability to communicate with other computer systems, for example, via the Internet. Depending on the functionality provided by the mobile device 201, in various embodiments the device 201 may be a multiple-mode communication device configured for both data and voice communication, a smartphone, a mobile telephone or a PDA (personal digital assistant) enabled for wireless communication, or a computer system with a wireless modem.

The mobile device 201 includes a rigid case (not shown) housing the components of the device 201. The internal components of the device 201 are constructed on a printed circuit board (PCB). The mobile device 201 includes a controller comprising at least one processor 240 (such as a microprocessor) which controls the overall operation of the device 201. The processor 240 interacts with device subsystems such as a wireless communication subsystem 211 (sometimes referred to as a radio layer) for exchanging radio frequency signals with the wireless network 101 to perform communication functions. The processor 240 interacts with additional device subsystems including a display screen 204 such as a liquid crystal display (LCD) screen, input devices 206 such as a keyboard and control buttons, flash memory 244, random access memory (RAM) 246, read only memory (ROM) 248, auxiliary input/output (I/O) subsystems 250, data port 252 such as serial data port, such as a Universal Serial Bus (USB) data port, speaker 256, microphone 258, short-range communication subsystem 262, and other device subsystems generally designated as 264. Some of the subsystems shown in FIG. 2 perform communication-related functions, whereas other subsystems may provide “resident” or on-device functions.

The device 201 may comprise a touch screen display in some embodiments. The touch screen display may be constructed using a touch-sensitive input surface connected to an electronic controller and which overlays the display screen 204. The touch-sensitive overlay and the electronic controller provide a touch-sensitive input device and the processor 240 interacts with the touch-sensitive overlay via the electronic controller. In some embodiments, a touch screen is integrated directly with the display. In still other embodiments, a touch screen is placed behind the display.

The communication subsystem 211 includes a receiver 214, a transmitter 216, and associated components, such as one or more antenna elements 218 and 220, local oscillators (LOs) 222, and a processing module such as a digital signal processor (DSP) 224. The antenna elements 218 and 220 may be embedded or internal to the mobile device 201 and a single antenna may be shared by both receiver and transmitter, as is known in the art. As will be apparent to those skilled in the field of communication, the particular design of the wireless communication subsystem 211 depends on the wireless network 101 in which mobile device 201 is intended to operate.

The mobile device 201 may communicate with any one of a plurality of fixed transceiver base stations 108 of the wireless network 101 within its geographic coverage area. The mobile device 201 may send and receive communication signals over the wireless network 101 after the required network registration or activation procedures have been completed. Signals received by the antenna 218 through the wireless network 101 are input to the receiver 214, which may perform such common receiver functions as signal amplification, frequency down conversion, filtering, channel selection, etc., as well as analog-to-digital (A/D) conversion. A/D conversion of a received signal allows more complex communication functions such as demodulation and decoding to be performed in the DSP 224. In a similar manner, signals to be transmitted are processed, including modulation and encoding, for example, by the DSP 224. These DSP-processed signals are output to the transmitter 216 for digital-to-analog (D/A) conversion, frequency up conversion, filtering, amplification, and transmission to the wireless network 101 via the antenna 220. The DSP 224 not only processes communication signals, but may also provide for receiver and transmitter control. For example, the gains applied to communication signals in the receiver 214 and the transmitter 216 may be adaptively controlled through automatic gain control algorithms implemented in the DSP 224.

The processor 240 operates under stored program control and executes software modules 221 stored in memory such as persistent memory, for example, in the flash memory 244. As illustrated in FIG. 2, the software modules 221 comprise operating system software 223, software applications 225 comprising an email messaging application 272 (also referred to as an email client 272), a personal address book 274, a calendar application 276, a phone application 278, and graphical authentication module 280. Example embodiments of the graphical authentication module 280 will be discussed in detail later herein. It is recognized that the graphical authentication module 280 and its various components as described herein can form a discrete module running on the device 201, or the functions of the graphical authentication module 280 can be distributed on the device 201 as separate modules or integrated within other existing modules as desired. Such discrete or distributed implementations all fall within the embodiments of the graphical authentication module 280 as described herein.

The software applications 225 also may include a range of applications, including, for example, a notepad application, Internet browser application, voice communication (i.e. telephony) application, mapping application, or a media player application, or any combination thereof. Each of the software applications 225 may include layout information defining the placement of particular fields and graphic elements (e.g. text fields, input fields, icons, etc.) in the user interface (i.e. the display screen 204) according to the application.

Those skilled in the art will appreciate that the software modules 221 or parts thereof may be temporarily loaded into volatile memory such as the RAM 246. The RAM 246 is used for storing runtime data variables and other types of data or information, as will be apparent to those skilled in the art. Although specific functions are described for various types of memory, this is merely one example, and those skilled in the art will appreciate that a different assignment of functions to types of memory could also be used.

In some embodiments, the auxiliary I/O subsystems 250 may comprise an external communication link or interface, for example, an Ethernet connection. The mobile device 201 may comprise other wireless communication interfaces for communicating with other types of wireless networks, for example, a wireless network such as an orthogonal frequency division multiplexed (OFDM) network or a GPS (Global Positioning System) subsystem comprising a GPS receiver or transceiver for communicating with a GPS satellite network (not shown). The auxiliary I/O subsystems 250 may comprise a pointing or navigational input device such as a touchpad, a clickable trackball or scroll wheel or thumbwheel, or a vibrator for providing vibratory notifications in response to various events on the device 201 such as receipt of an electronic message or incoming phone call, or for other purposes such as haptic feedback (touch feedback).

In some embodiments, the mobile device 201 also includes a removable memory card or module 230 (typically comprising flash memory) and a memory card interface 232. Network access is typically associated with a subscriber or user of the mobile device 201 via the memory card 230, which may be a Subscriber Identity Module (SIM) card for use in a GSM network or other type of memory card for use in the relevant wireless network type. The memory card 230 is inserted in or connected to the memory card interface 232 of the mobile device 201 in order to operate in conjunction with the wireless network 101.

The mobile device 201 also stores other data 227 in an erasable persistent memory, which in one example embodiment is the flash memory 244. In various embodiments, the data 227 includes service data comprising information required by the mobile device 201 to establish and maintain communication with the wireless network 101. The data 227 may also include user application data such as email messages, address book and contact information, calendar and schedule information, notepad documents, image files, and other commonly stored user information stored on the mobile device 201 by its user, and other data. The data 227 stored in the persistent memory (e.g. flash memory 244) of the mobile device 201 may be organized, at least partially, into a number of databases each containing data items of the same data type or associated with the same application. For example, email messages, contact records, and task items may be stored in individual databases within the device memory.

The mobile device 201 also includes a battery 238 as a power source, which is typically one or more rechargeable batteries that may be charged, for example, through charging circuitry coupled to a battery interface such as the serial data port 252. The battery 238 provides electrical power to at least some of the electrical circuitry in the mobile device 201, and the battery interface 236 provides a mechanical and electrical connection for the battery 238. The battery interface 236 is coupled to a regulator (not shown) which provides power V+ to the circuitry of the mobile device 201.

The short-range communication subsystem 262 is an additional optional component which provides for communication between the mobile device 201 and different systems or devices, which need not necessarily be similar devices. For example, the subsystem 262 may include an infrared device and associated circuits and components, or a wireless bus protocol compliant communication mechanism such as a Bluetooth® communication module to provide for communication with similarly-enabled systems and devices.

A predetermined set of applications that control basic device operations, including data and voice communication applications will normally be installed on the mobile device 201 during or after manufacture. Additional applications and/or upgrades to the operating system 221 or software applications 225 may also be loaded onto the mobile device 201 through the wireless network 101, the auxiliary I/O subsystem 250, the serial port 252, the short-range communication subsystem 262, or other suitable subsystem 264. The downloaded programs or code modules may be permanently installed, for example, written into the program memory (i.e. the flash memory 244), or written into and executed from the RAM 246 for execution by the processor 240 at runtime. Such flexibility in application installation increases the functionality of the mobile device 201 and may provide enhanced on-device functions, communication-related functions, or both. For example, secure communication applications may enable electronic commerce functions and other such financial transactions to be performed using the mobile device 201.

The mobile device 201 may provide two principal modes of communication: a data communication mode and a voice communication mode. In the data communication mode, a received data signal such as a text message, an email message, or Web page download will be processed by the communication subsystem 211 and input to the processor 240 for further processing. For example, a downloaded Web page may be further processed by a browser application or an email message may be processed by the email messaging application and output to the display 204. A user of the mobile device 201 may also compose data items, such as email messages, for example, using the input devices in conjunction with the display screen 204. These composed items may be transmitted through the communication subsystem 211 over the wireless network 101.

In the voice communication mode, the mobile device 201 provides telephony functions and operates as a typical cellular phone. The overall operation is similar, except that the received signals are output to the speaker 256 and signals for transmission are generated by a transducer such as the microphone 258. The telephony functions are provided by a combination of software/firmware (i.e., the phone application 278) and hardware (i.e., the microphone 258, the speaker 256 and input devices). Alternative voice or audio I/O subsystems, such as a voice message recording subsystem, may also be implemented on the mobile device 201. Although voice or audio signal output is typically accomplished primarily through the speaker 256, the display screen 204 may also be used to provide an indication of the identity of a calling party, duration of a voice call, or other voice call related information.

The phone application 278 can be split into multiple applications or sub-modules, for example one or more user phone modules and a call control module. The user phone modules provide a variety of telephony features through a user interface, while the call control module provides access to common telephony functions desired by the user phone modules, such that telephony requests from phone modules can be coordinated and so that the user phone modules do not need to each provide instructions understood by the wireless communications subsystem 211. The call control function typically makes telephony features available to user phone modules through an application programming interface (API). It is to be recognized that all or part of the phone application 278 features or functions could be provided through the operating system or otherwise distributed in the device 201, while continuing to fall within the term phone application 278.

Referring now to FIG. 3, an exemplary computer readable media 310 will be described. The computer readable media 310 have computer readable instructions 320 stored thereon that when implemented cause a processor 330 to execute any one of the methods described herein. For the purposes of the application, computer readable media comprise any tangible computer storage, such as but not limited to flash memory, read only memory, CD, DVD and memory sticks. Graphical authentication module 280 described above with reference to FIG. 2 is an exemplary implementation of computer readable media 310. However, it is to be understood that the computer readable media 310 is not limited to use on mobile devices, such as mobile device 210 described above. Non-limiting examples of the processor 330 include a CPU (central processing unit) on a personal computer, laptop computer, tablet device, personal digital assistant (PDA), mobile telephone, smart phone, bank machine, digital authentication system for entry to rooms or buildings, or control system. Any device with a processor, a display and a user interface enabling a user to move images on the display could feasibly make use of the computer readable media 310 to authenticate users.

A flow chart of a method implemented by the processor 330 is shown in FIG. 4A. The method is a method of authenticating a user of a computing device, the computing device having a memory storing a base image and an overlay image, the base image having a pre-selected base image reference point, and the overlay image having an overlay image reference point. The method starts with generating 410 a modified base image and generating 420 a modified overlay image. Then the method continues with displaying 430, on a display, the modified base image overlaid by the modified overlay image. Action 440 of the method is receiving an input for moving one of the modified base image and the modified overlay image. Then the method continues with moving 450 the one of the modified base image and the modified overlay image in response to the input. Then at action 460, in response to alignment of the base image reference point with the overlay image reference point on the display, indicating positive authentication, at least one of the base image reference point and the overlay image reference point having coordinates in three dimensions. Non-limiting examples of indicating positive authentication include: providing a visual indicator; providing an audible indicator; and allowing user access.

Referring now to FIG. 4B, another example method will be described. The method in FIG. 4B starts with actions 410, 420, 430, 440, and 450 from FIG. 4A. Then, after receiving the further input, a determination 455 is made of whether or not alignment is achieved of a first point on the modified base image with a second point on the modified overlay image. If the determination is that there is alignment, the method proceeds to action 460 which is the same as action 460 in FIG. 4A, that is indicating positive authentication. If there is no alignment, the method proceeds to indicating 470 that authentication failed.

The indication that authentication failed in some embodiments is an audio signal. In some embodiments, the indication that authentication failed is a visual output on the display. In some embodiments, if authentication failed, the method starts over. In some embodiments, after a set number of failed authentication attempts, a user is locked out and not permitted to attempt authentication again. In some embodiments, the user is locked out until an administrator overrides the lock out. In other embodiments, the lock out is for a set time period.

In some embodiments the method further comprises timing the authentication attempt. If positive authentication is not indicated within a time limit, the method proceeds to action 470, i.e. indicating that authentication failed.

In an alternate embodiment, when the overlay image is moved, the modified base image disappears. In other words, the moving comprises moving the overlay image and the method further comprises removing the modified base image from the display in response to receiving the input. Therefore, the user must remember where the base image reference point was located on the display and align the overlay image reference point without being able to see it. This adds security in that a third party can not see any two points being aligned. However, tolerances for alignment would likely be less strict than in the case where the user can see the base image reference point.

In some embodiments, the modified base image is displayed to have a three-dimensional appearance. For example, the image in some embodiment is drawn to have the appearance of depth. In some embodiments, three-dimensional data is stored for the modified base image and a marker such as a cursor or a reference point on the overlay image can be moved to co-ordinates in all three dimensions on the base image. For example, one input mechanism could be used to move the modified overlay image from side to side and up and down on the display with respect to the modified base image. Another input mechanism could be used to move the overlay image in or out of the modified base image. It is to be understood that in some embodiments, it is the modified base image that is moved. Additionally, in some embodiments, the modified base image can be rotated so that points hidden in the original view can be seen, such as another side of a building. In some embodiments, a single input mechanism is used to move the image that is being moved in all three dimensions. For example, a joy stick is used in some embodiments.

In some embodiments the images are displayed on a three dimensional display, such as but not limited to a display using parallax technology. In some embodiments, the three dimensional images can be manipulated using a three dimensional interface. In some embodiments, the images appear to be popping out of the display. In some embodiments, at least one of the images can be manipulated using hand gestures above the display. Hand gestures can be captured in a number of manners, including but not limited to proximity sensors and cameras.

In some embodiments, the method further comprises comparing a first angle from which alignment is reached with a second angle from which a previous alignment was reached and only indicating positive authentication if the first angle and the second angle are different. In a non-limiting example, the base image reference point is a window on a building, and the angle from which the overlay image reference point approaches that window for alignment must vary from one authentication attempt to another. In some embodiments the previous alignment is from an immediately preceding authentication attempt. Referring to the previous example, for instance, if the overlay image reference point approaches the window from below in one authentication attempt, the next authentication attempt could be an approach from above or one of the sides. In some embodiments, where a sequence of alignments is required for one authentication, the first angle and the second angle could each be from a different alignment in the sequence.

In non-limiting exemplary embodiments, the base image is a photograph of a scene and the pre-selected reference point is an object or portion of an object in the scene. In other non-limiting embodiments, the base image includes a plurality of abstract objects and the pre-selected reference point is one of the abstract objects. In other embodiments, the base image is a grid of numbers, characters or objects.

In non-limiting embodiments, the overlay image is a grid of numbers, characters or objects. In some embodiments, the pre-selected number, character or object appears more than once in the grid. As with the base image, in some embodiments the pre-selected image in some embodiments is a photo or abstract image. In some cases, when the image is overlaid on the base image, it is presented so that the base image or portions thereof are visible through the overlay image.

In some embodiments, the reference point on either the base image or the numbers on the overlay image or both are represented by a dot, an x or some other symbol next to a recognizable part of the image, such as a number, character, or object. In some embodiments, the dot, x or other symbol appears next to some or all other objects in the modified base image or the modified overlay image. In some embodiments, aligning the numbers with the base image reference point includes bringing one of the references points within a predefined distance of the other reference point. In other words, there may be a tolerance zone. An example of a tolerance zone is an area around a reference point in which a user selection will be interpreted as selection of the reference point. The tolerance zone can be made smaller for increased security or larger where less precision is possible. In some embodiments, the tolerance zone is variable and is made smaller when increased security is required.

While the methods described with reference to FIGS. 4a and 4b refer to one base image and one overlay image and a single reference point on each image, it is to be understood that any number of images and reference points can be used. It is to be understood that the methods described herein are not limited to the order in which the actions are presented herein and that the various actions may be implemented in a different order in other embodiments.

In some example embodiments, the computer readable media 310 is located on the computing device. FIG. 5 shows a computing device 500 with computer readable media 310 installed thereon. The computing device 500 also comprises a memory 510 on which the base image 511 and the overlay image 521 are stored. Non-limiting examples of formats for storing the base image 511 and the overlay image 521 are bitmap, PDF, JPEG, and PNG. In some embodiments, for example where a grid is used, the format of the image can include different fonts or font technologies. In some embodiments, the memory 510 is an external memory, such as a memory stick or a memory on a server. A display 530 is also provided for displaying representations or modified versions of the base image 511 and the overlay image 521. In some embodiments, the display is a touchscreen. In some embodiments the display is a multi-touch screen. In some embodiments, the display is a 3-D screen.

In some embodiments, one or both of the overlay image and the base image stored in the memory comprise data and/or instructions for generating the respective image. For example, the stored image can comprise instructions to generate a 2D grid of numbers from 1 to 100.

In some embodiments of the computer readable media 310, generating the modified base image comprises randomly altering the position of the base image reference point on the display. In some embodiments, the base image reference point is altered with respect to the rest of the base image. In other embodiments, generating the modified overlay image comprises randomly altering the position of the overlay image reference point. In some embodiments, both the base image reference point and the overlay image reference point positions are altered.

In some embodiments, one or both of the overlay image and the base image are distorted. Examples of altering the image include but are not limited to stretching the image (rubber band effect), blurring portions of the image, compressing the image and morphing the image. Another example involves generating a collage of images from the base image or overlay image, where the collage can be reconfigured. In such an embodiment, in presenting the collage or modified image, the respective reference points should be visible and not overlapped. In some embodiments, if the reference point is a number or character, the font can be changed.

In some embodiments, generating the modified base image comprises making a copy of the base image. In some embodiments, the copy is an exact copy. Likewise, in some embodiments, generating the modified overlay image comprises making a copy of the overlay image and the copy of the overlay image, in some cases, can be an exact copy of the overlay image.

Non-limiting examples of presenting the modified images include presenting the respective image at a different location each time the instructions are executed, distorting the appearance of the image and rotating the modified image.

In some embodiments of the computer readable media 310, the input comprises a movement of the modified base image and a movement of the modified overlay image. The modified images are moved by the user using navigation controls on the computing device in some embodiments. For example, a mouse can be used to click and drag the image to be moved. If a touch screen is used, the user can touch and drag one or both images. Other non-limiting navigation controls include keys on a keyboard, a touchpad, a trackball, a thumbwheel and a joystick. In an exemplary embodiment, the input comprises a sequence of movements of the base image and the overlay image. In some embodiments, the representations of the images must be moved in a specific sequence. For example, first move one of the modified base image and the modified overlay image and then move the other of the two so that the respective reference points are aligned. In an exemplary embodiment, individual touch is used to move both planes, i.e. the base image plane and the overlay image plane. In some embodiments, each plane can be moved simultaneously by a different finger if multi-touch input is supported. Some embodiments restrict the movement of each representation in horizontal, diagonal or vertical directions.

In some embodiments, gestures are used to move the modified base image or the modified overlay image or both. For example, pressure or an accelerometer can control the movement.

Screen wrap can also be used in some embodiments to confuse third party observers. Screen wrap can be used in at least two manners. In the first, when part of the image moves off one edge of the display, that part appears immediately on the opposite side. In the first manner, the image is usually the same size as the display. In the second manner, which is sometimes used when the image is larger than the display, part of the image moves off the edge but is not seen immediately on the opposite side. In this case, the third party observer would not see the entire image. In some such embodiments, one or more of the reference points may not be visible on the screen at first and the user has to move the representation of the respective image to bring the reference point into view.

In one embodiment, the overlay image is a grid of numbers and when the modified overlay image is displayed, the grid could move up or down with only a portion of the grid visible, i.e. higher or lower numbers may not be visible. The user moves the grid to align the pre-selected number with the reference point on the modified base image. In some embodiments, the pre-selected number must be moved up or down to the proper height and then moved left or right to align with the reference point on the base image. The requirement to move a reference point vertically and then horizontally or vice versa can be used in any embodiment and is not limited to a grid of numbers.

Panoramic photos can also be used for either the base image or the overlay image or both. In some such embodiments, the photo is moveable to align the reference points. In some embodiments, the photo is moveable to align a point on the photo with a number on a grid. In some embodiments, the photo is moveable to align a point on the photo with a column and row in a grid corresponding to a pre-selected number. In other embodiments, the photo is moveable left or right only. In other embodiments, the photo is moveable up and down only. In still other embodiments, the photo is moveable in and out of the display.

In some embodiments, the overlay image is a grid of images and presenting the modified overlay image comprises altering the position of the pre-selected overlay image reference point while maintaining at least one of a column and a row with images having a common characteristic. In an exemplary embodiment, the grid is a grid of numbers with all of the “x1s” in one column (1, 11, 21, etc.) and all of the “x2s” in another column (2, 12, 22, etc) and so on, but the position of each number with the respective column changes each time the instructions are executed. For example, if the grid is a grid of numbers and the pre-selected reference point on the overlay image is the number 23, each time the grid is presented the reference point will be in a different row and column, but always in the same column as the “20s” and the same row as the “x3s”. If the grid consists of shapes of varying sizes, colours or other features, a feature (square shape, for example) could always be in the same column but the position in the column could change. Maintaining the reference point in a column or row with points of a common characteristic provides some assistance to the user in finding the reference point while maintaining the added security of randomly altering the location of the reference point.

In still another embodiment, the grid is randomly generated in response to a user input, such as, but not limited to, a gesture, selecting a key, and a sequence of keystrokes. For example, with a device with an accelerometer, shaking could reset the grid. In other embodiments, the modified base image or the modified overlay image or both could be programmed to reset after a predetermined period of time.

Referring to FIG. 6, a computing device 600 will be described. In some embodiments the computing device 600 is a mobile communications device such as the mobile device 201 described herein. However, it is to be understood that the computing device 600 can be any computing device. Non-limiting examples include a personal computer, laptop computer, tablet device, personal digital assistant (PDA), mobile telephone, smart phone, bank machine, an access device for allowing access to a building or room, and an electronic controller for controlling systems or equipment.

The computing device 600 comprises the graphical computer readable media 310, a user interface 610, a display 620, and a processor 630. In some embodiments, a user interface 610 is provided for receiving user instructions to align the base image reference point and the overlay image reference point. In some embodiments, the user interface is a touch screen. The display 620 is used to display the modified base image and the modified overlay image. In some embodiments, the user interface is part of the display. The processor 630 for executing the instructions. In some embodiments, the computing device 600 also comprises the first memory and the second memory. The computing device 600, in some embodiments also comprises a flash memory on which the authentication module is located.

In some embodiments, dedicated controls are provided on the computing device 600 for moving the representations of the base image or the overlay image or both.

It is to be understood that the embodiments described herein are not limited to one base image and one overlay image. Multiple layers of images are possible. Furthermore, multiple reference points on each layer are also possible.

Referring now to the screens shots of FIGS. 7A to 7D, a specific implementation of a proposed method will be described. FIG. 7A shows a base image 700, including a number of objects displayed to have a 3-D appearance on a 2-D display. Points on the objects can be selected as a reference point. For illustrative purposes the base image shown includes a four story building with windows and a door that can be selected, a house with windows, a door and chimney that can be selected, a tree with fruit that can be selected and an airplane with windows and symbols that can be selected. In some embodiments, the objects can be rotated to select objects on other sides of the objects. In this example, the user has selected a window 710 on the left side of the building as the base image reference point. In FIG. 7B, an overlay image 720 which is a grid 724 of numbers from 1 to 12 is shown. Number 8 has been selected as the overlay image reference point 722. Referring to FIG. 7C, to start the authentication of the user, a modified base image 730 is presented overlaid with a modified overlay image 740. In the modified base image 730, the position of the building with the window 710 has been altered. In some embodiments, the position of the base image reference point 710 varies with each authentication attempt. It is to be understood that the positions of the other objects in the modified base image can be altered as well. In other embodiments, the modified base image remains the same with each authentication. In modified overlay image 740, the order of the numbers in the grid 724 has been altered, so that the numbers are in a different position. It is to be understood that in some embodiments, the order of the numbers in the grid 724 remains the same. In some embodiments, the numbers can appear more than once in the modified overlay image. Referring to FIG. 7D, the modified overlay image is moved so that the overlay image reference point 722, number 8, is aligned with the base image reference point 710, the window.

In some embodiments, the modified base image and the overlay image are displayed in 3-D. Screen shots of the embodiment described with reference to FIGS. 7A to 7D applied with three dimensional images is shown in FIGS. 8A and 8B. In some embodiments, the 3-D images can be manipulated above the display using a 3-D interface. For example, one or both of the images can be rotated. In another example, translation of an image is possible. In some embodiments, the 3-D manipulation is accomplished using hand gestures.

While the present disclosure is sometimes described in terms of methods, a person of ordinary skill in the art will understand that the present disclosure is also directed to various apparatus including components for performing at least some of the aspects and features of the described methods, be it by way of hardware components, software or any combination of the two, or in any other manner. Moreover, an article of manufacture for use with the apparatus, such as a pre-recorded storage device or other similar computer readable medium including program instructions recorded thereon may direct an apparatus to facilitate the practice of the described methods. It is understood that such apparatus and articles of manufacture also come within the scope of the present disclosure.

The various embodiments presented above are merely examples and are in no way meant to limit the scope of this disclosure. Variations of the innovations described herein will be apparent to persons of ordinary skill in the art, such variations being within the intended scope of the present application. In particular, features from one or more of the above-described embodiments may be selected to generate alternative embodiments comprised of a sub-combination of features which may not be explicitly described above. In addition, features from one or more of the above-described embodiments may be selected and combined to generate alternative embodiments comprised of a combination of features which may not be explicitly described above. Features suitable for such combinations and sub-combinations would be readily apparent to persons skilled in the art upon review of the present application as a whole. The subject matter described herein and in the recited claims intends to cover and embrace all suitable changes in technology. 

The invention claimed is:
 1. A method of controlling access to an electronic device, the method comprising: displaying, on a three-dimensional display of the electronic device, a digital image overlaid by an array of alphanumeric characters, wherein the digital image comprises a digital photograph or computer-generated image, wherein the digital image includes a three-dimensional representation of a visual scene comprising a number of visual elements and is displayed on the three-dimensional display of the electronic device in three-dimensional coordinates, wherein the digital image can be manipulated in three dimensions to display the visual scene from different perspectives; receiving an input representative of moving the digital image being displayed on the three-dimensional display; repositioning the digital image being displayed on the three-dimensional display in response to the received input representative of moving the digital image being displayed on the three-dimensional display; repositioning the array of alphanumeric characters displayed on the three-dimensional display with respect to the digital image in response to received input; detecting alignment of a designated character in the array with a designated visual element in the visual scene of the digital image in response to the repositioning the digital image and the array, wherein the designated character in the array is aligned with the designated visual element in the digital image by the designated character in the array being within a designated threshold distance of the designated visual element in the digital image; and authenticating access to the electronic device in response to detecting that the designated character in the array is aligned with the designated visual element in the digital image.
 2. The method of claim 1, wherein the array of alphanumeric characters is displayed in three-dimensional coordinates.
 3. The method of claim 1, wherein the array of alphanumeric characters is repositioned using gestures detected using proximity sensors and/or cameras.
 4. The method of claim 1, further comprising: generating the array of alphanumeric characters from a reference array of alphanumeric characters, the generating including modifying a position of the designated character in the reference array of alphanumeric characters so that the designated character in the array of alphanumeric characters image has a modified location relative to its position in the reference array of alphanumeric characters.
 5. The method of claim 4, further comprising: generating the digital image from a reference digital image, the generating including modifying a position of the designated visual element in the reference digital image so that the designated visual element in the digital image has a modified location relative to its position in the reference digital image.
 6. The method of claim 1, further comprising: generating the digital image from a reference digital image, the generating including modifying a position of the designated visual element in the reference digital image so that the designated visual element in the digital image has a modified location relative to its position in the reference digital image.
 7. The method of claim 1, wherein the array of alphanumeric characters is provided by an image that is transparent except for a plurality of characters.
 8. The method of claim 1, wherein the alphanumeric characters in the array of alphanumeric characters elements are arranged in rows and columns.
 9. The method of claim 1, further comprising: comparing a first angle from which alignment is reached with a second angle from which a previous alignment was reached and only authenticating access to the electronic device in response to the first angle and the second angle being different.
 10. The method of claim 9, wherein the previous alignment is from an immediately preceding authentication attempt.
 11. The method of claim 1, wherein the designated threshold distance is set based on a security setting of the electronic device.
 12. The method of claim 1, further comprising: removing, from the three-dimensional display, the digital image in response to the received input to move the array of alphanumeric characters.
 13. The method of claim 1, comprising moving, in three dimensions, the digital image displayed on the three-dimensional display in response to received input to display the designated visual element in the visual scene of the digital image in the three-dimensional display.
 14. The method of claim 1, wherein the designated visual element has three-dimensional coordinates, and the designated character has three-dimensional coordinates, wherein the method comprises aligning the three-dimensional coordinates of the designated visual element and the three-dimensional coordinates of the designated character.
 15. The method of claim 1, wherein: the designated character of the array is a first designated character, the array having a second designated character; and the designated visual element of the digital image is a first designated visual element, the digital image having a second designated visual element; and the method comprising: detecting alignment of the first designated character in the array with the first designated visual element of the digital image and alignment of the second designated character in the array with the second designated visual element of the digital image in response to the moving of the digital image and the moving of the array; and authenticating access to the electronic device in response to detecting that the first designated character in the array is aligned with the first designated visual element in the digital image, and that the second designated character in the array is aligned with the second designated visual element in the digital image.
 16. An electronic device, comprising: a processor; a three-dimensional display coupled to the processor; a memory coupled to the processor storing instructions that, in response to execution by the processor, cause the electronic device to: display, on the three-dimensional display, a digital image overlaid by an array of alphanumeric characters, wherein the digital image comprises a digital photograph or computer-generated image, wherein the digital image includes a three-dimensional representation of a visual scene comprising a number of visual elements and is displayed on the three-dimensional display of the electronic device in three-dimensional coordinates, wherein the digital image can be manipulated in three dimensions to display the visual scene from different perspectives; receive an input representative of moving the digital image being displayed on the three-dimensional display; reposition the digital image being displayed on the three-dimensional display in response to the received input representative of moving the digital image being displayed on the three-dimensional display; reposition the array of alphanumeric characters displayed on the three-dimensional display with respect to the digital image in response to received input; detect alignment of a designated character in the array with a designated visual element in the visual scene of the digital image in response to the repositioning the digital image and the array, wherein the designated character in the array is aligned with the designated visual element in the digital image by the designated character in the array being within a designated threshold distance of the designated visual element in the digital image; and authenticate access to the electronic device in response to detecting that the designated character in the array is aligned with the designated visual element in the digital image.
 17. The electronic device of claim 16, wherein the instructions, in response to execution by the processor, cause the electronic device to: compare a first angle from which alignment is reached with a second angle from which a previous alignment was reached and only authenticating access to the electronic device in response to the first angle and the second angle being different.
 18. The electronic device of claim 16, wherein the instructions, in response to execution by the processor, cause the electronic device to move, in three dimensions, the digital image displayed on the three-dimensional display in response to received input to display the designated visual element in the visual scene of the digital image in the three-dimensional display.
 19. The electronic device of claim 16, wherein the designated visual element has three-dimensional coordinates, and the designated character has three-dimensional coordinates, and wherein the instructions in response to execution by the processor, cause the electronic device to align the three-dimensional coordinates of the designated visual element and the three-dimensional coordinates of the designated character.
 20. The electronic device of claim 16, wherein: the designated character of the array is a first designated character, the array having a second designated character; and the designated visual element of the digital image is a first designated visual element, the digital image having a second designated visual element; and wherein the instructions, in response to execution by the processor, cause the electronic device to: detect alignment of the first designated character in the array with the first designated visual element of the digital image and alignment of the second designated character in the array with the second designated visual element of the digital image, in response to the moving of the digital image and the moving of the array; and authenticate access to the electronic device in response to detecting that the first designated character in the array is aligned with the first designated visual element in the digital image, and that the second designated character in the array is aligned with the second designated visual element in the digital image.
 21. A non-transitory machine readable medium having tangibly stored thereon executable instructions that, in response to execution by a processor of an electronic device, cause the electronic device to: display, on a three-dimensional display of the electronic device, a digital image overlaid by an array of alphanumeric characters, wherein the digital image comprises a digital photograph or computer-generated image, wherein the digital image includes a three-dimensional representation of a visual scene comprising a number of visual elements and is displayed on the three-dimensional display of the electronic device in three-dimensional coordinates, wherein the digital image can be manipulated in three dimensions to display the visual scene from different perspectives; receive an input representative of moving the digital image being displayed on the three-dimensional display; reposition the digital image being displayed on the three-dimensional display in response to the received input representative of moving the digital image being displayed on the three-dimensional display; reposition the array of alphanumeric characters displayed on the three-dimensional display with respect to the digital image in response to received input; detect alignment of a designated character in the array with a designated visual element in the visual scene of the digital image in response to the repositioning the digital image and the array, wherein the designated character in the array is aligned with the designated visual element in the digital image by the designated character in the array being within a designated threshold distance of the designated visual element in the digital image; and authenticate access to the electronic device in response to detecting that the designated character in the array is aligned with the designated visual element in the digital image.
 22. The non-transitory machine readable medium of claim 21, wherein the array of alphanumeric characters is displayed in three-dimensional coordinates.
 23. The non-transitory machine readable medium of claim 21, wherein the instructions, in response to execution by the processor, cause the electronic device to move, in three dimensions, the digital image displayed on the three-dimensional display in response to received input to display the designated visual element in the visual scene of the digital image in the three-dimensional display.
 24. The non-transitory machine readable medium of claim 21, wherein the designated visual element has three-dimensional coordinates, and the designated character has three-dimensional coordinates, and wherein the instructions, in response to execution by the processor, cause the electronic device to align the three-dimensional coordinates of the designated visual element and the three-dimensional coordinates of the designated character.
 25. The non-transitory machine readable medium of claim 21, wherein: the designated character of the array is a first designated character, the array having a second designated character; and the designated visual element of the digital image is a first designated visual element, the digital image having a second designated visual element; and wherein the instructions, in response to execution by the processor, cause the electronic device to: detect alignment of the first designated character in the array with the first designated visual element of the digital image and alignment of the second designated character in the array with the second designated visual element of the digital image, in response to the moving of the digital image and the moving of the array; and authenticate access to the electronic device in response to detecting that the first designated character in the array is aligned with the first designated visual element in the digital image, and that the second designated character in the array is aligned with the second designated visual element in the digital image. 